The present invention relates to a coupling for connecting a spray apparatus capable of discharging and/or replenishing a fluid by pressing a nozzle projecting from an end portion of the spray apparatus, to a fluidic apparatus, and more particularly to a coupling capable of performing a discharging operation and an replenishing operation of the spray apparatus in a state of connecting the spray apparatus with the fluidic apparatus, such as a pneumatic tool.
As shown in FIG. 7, conventionally, when a fluid (for example, a washing agent, a lubricating agent, an anticorrosive agent and the like) is injected into an pneumatic tool 19 powered by a compressed air from a spray can by pressing a nozzle 181 projecting at a spray end portion 180, a resin cap 182 provided on the spray can 18 is interposed between the spray can 18 and the tool 19.
The cap 182 is structured such that a recess portion 183 to which the spray end portion 180 of the spray can 18 is inserted is formed in a top plate, that a lock hook 188 adhering the spray can 18 is provided in three portions of a peripheral surface of the recess portion 183, that a through hole 184 to which the nozzle 181 is inserted is provided in a center portion of the recess portion 183, that a cylinder portion 185 having a diameter smaller than an inner diameter of a plug body 190 provided in the air tool 19 is provided in a projecting manner, that a holding cylinder portion 186 engageable with the plug body 190 is provided in a projecting manner, and that an inward flange portion 187 having an opening diameter larger than an opening diameter of the nozzle 181 is formed in a front end of the cylinder portion 185. In this case, a center portion of a surface of the recess portion 183 is formed in a taper shape so as to easily insert the nozzle 181 into the through hole 184.
In a use method, at first, a plug body 190 of the air tool 19 is fitted into the holding cylinder portion 186 of the cap 182 so that the air tool 19 and the cap 182 are connected to each other. Next, the nozzle 181 of the spray can 18 is inserted into the through hole 184 open to the center of the recess portion 183 of the cap 182, so that the front end portion of the nozzle 181 is brought into contact with the flange portion 187 provided in the front end of the cylinder portion 185. Further, as well as in this state, the spray can 18 is pressed and the lock hook 188 is brought into contact with the spray end portion 180, the flange portion 187 presses the nozzle 181 so as to open a valve normally set in a closed state and disposed therewithin and the fluid is discharged from the front end of the nozzle 181 in a state that the spray can 18 is in an inserted state, so that the fluid is injected into the air tool 19.
However, in accordance with the conventional spray can method, there is a problem mentioned below. Accordingly, when the nozzle 181 is inserted into the through hole 184 of the cylinder portion 185 formed in the cap 182, there is a case that the nozzle 181 is erroneously pressed and the fluid is carelessly discharged out, and further, since the cylinder portion 185 and the front end portion of the plug body 190, and the holding cylinder portion 186 and the plug body 190 are respectively in contact with each other in a fitting manner, a sealing performance is deteriorated and there is a risk that a fluid leaks from these portions.
Further, since the spray can 18 and the cap 182 are attached to each other in a fitting manner by the lock hooks 188 at a time of inserting the spray can 18 into the cap 182, the fluid is kept in an injecting state from the nozzle 181, so that in the case of stopping the injection of the fluid, it is necessary to remove the spray can 18 from the cap 182 each time, and further, there is a problem that the fluid is carelessly leaked out from the body of the air tool 19 by a backward flow.
Still further, there is a problem that in the case that an air intake port and an air exhaust port of the air tool 19 are provided in the same surface, the cap 182 can not be connected to the plug body 190.